Cuffless and non-invasive Systolic Blood Pressure estimation for aged class by using a Photoplethysmograph

This study provides cuffless and non-invasive technique of Systolic Blood Pressure (SBP) estimation by using only a Photoplethysmography (PPG) sensor. As people get older, cardiovascular peculiarities are changing more and more, so this study focuses on the presumption of SBP in old age. Ages 60 and over were defined as old age and grouped into an aged class in this study, ages fewer than 60 were grouped into a young-middle class. The measured data in this experiment were both Capacity Pulse Wave (PW) and SBP. PW was obtained by the PPG and SBP was obtained by the commercial Blood Pressure (BP) meter with a cuff. Then the regression equation of SBP was calculated from individual information and features of PW. 96 healthy volunteers participated in the BP and PW measurement experiment. This result implied that patients' cardiovascular peculiarities change according to aging and vary among difference individuals. Furthermore, the data of old age were classified into four classes through a boundary values that depend on b and d of Acceleration Pulse Wave (APW). As regards the result of the aged class, the measured SBP was significantly correlated with the presumed SBP (r=0.89, SD=8.2mmHg) and the SD was 5.5 mmHg better than the SD of non-classified data. In conclusion, it is quite important for SBP estimation to divide data into several classes by age. Besides, the classification by using the parameters with the features of APW as individual cardiovascular peculiarities is a hopeful technique for the aged class. Therefore, the proposed techniques are quite promising and useful for the feature studies on cuffless and continuous BP monitoring.